Ten years ago today, I was sitting in a movie theater in Times Square with every single muscle in my body tensed and contracting, like threads on a wool sweater in the dryer. This was before movie-theater seats got nice and cushy and wide and you could put your feet up, so when I tell you that my feet were up on my seat and my knees were nearly up to my chin, know that this was only possible because fear had entered my body and was pretzeling it as it saw fit. This was all happening the very first time I saw The Strangers, and in the decade since its release, no horror film has scared me more nor been as effective at showing human terror at its most unexplainable.

The plot to The Strangers is incredibly simple. An unhappy couple on the precipice of breaking up — we meet them on the way home from a friend’s wedding reception; he’s proposed to her and she’s declined — staying at a semi-familiar summer home for the night find themselves terrorized by a trio of masked strangers who seem to have no agenda at all except murder and mayhem. That’s it. Can James (Scott Speedman) and Kristen (Liv Tyler) make it out alive? It’s that simple, and that is terrifying.

There are no big moves in The Strangers. No horrible revelations and no reasons either. But what director Bryan Bertino does with details — small moments, indelible art direction, playing with expectations — produces a whole that is so much greater than the sum of its parts. It starts right at the beginning, with James and Kristen’s tense, almost traumatized silence towards each other. It’s already the worst night of their lives before the horror even begins. Subtly, we’ve been made to care about these people, which isn’t a matter of getting to like them, exactly, but seeing them as recognizable people whose experiences aren’t unlike our own. Then … Tamara.

It’s all, again, so simple. A knock on the door at 4am in the summer house on a dead-quiet street. We’ve all been at that house in some iteration or another, and the idea that someone would come up and knock on the door is unsettling enough as it is. That it’s this stoner-sounding girl with a barely audible croak of a voice asking if Tamara is home is somehow the most terrifying thing, and not just because we know what’s next. It’s the context-less-ness of it all that truly chills. (That she says “See you later”? Can’t even get into it!) Who is she? Who is Tamara? Why doesn’t she know where Tamara lives? Or does she know and they’re being messed with?

It’s of course that last one, and as harbingers of doom in a horror movie go, this one’s pretty unforgettable. But the single scene in The Strangers that has burned itself onto my psyche forevermore is of course the scene where Kristen is in the kitchen, smoking a cigarette. James has gone out to get more smokes, partly because Kristen wants them and partly because he’s being passive-aggressive, and now Kristen is home alone and unsettled but not yet scared. We in the audience are about to get for real scared, though. This clip of a theater audience reacting to what happens next is perfectly emblematic about what this scene does to people the first time they see it.

This is all before any act of violence has happened! And there are some acts of violence in this movie. Though it possesses an ability to scare you with simply a creak or a scratch or a music choice, The Strangers is up to some brutality. As horror movies go, the violence isn’t as over-the-top as some, but it’s so grounded in terrified reality that it hits harder than most. This isn’t some final-girl teen slasher where the audience thrills as the protagonists are knocked off one by one. (Though there is, in fact, a Final Girl.) There is no greater message at play. The Strangers is going to scare the living hell out of you simply by making you walk out of that theater without a single shred of a thought that this couldn’t happen to you. That this couldn’t be lurking outside your window at any time. Knock-knock.